Ozone treatment pak choi for the removal of malathion and carbosulfan pesticide residues

•QuEChERS pretreatment and LC/MS technology were used to detect the residues. The effects of ozone treatment on pesticide residues in pak choi were investigated.•The pesticide degradation was fitted to the “first + first”-order kinetic model.•The differences between the degradation of two pesticides were analyzed deeply.